Besides abundant H and He, 114 interstellar and circumstellar gas phase molecules are currently identified along with a small fraction (~1% by mass) of interstellar dust composed of a mixture of materials from various sources. The formation of complex molecules occurs already during the evolutionary cycle of interstellar icy grains which are originally formed in dark clouds. The icy grain mantles may be processed by ultraviolet irradiation and heated, and return complex molecules to the interstellar gas. An important constraint for the link between interstellar and Solar System material as well as the origin and evolution of comets is to search for pre-solar ices, organics and minerals to obtain evidence to what extent they have been preserved in Solar System bodies. The Infrared Space Observatory ISO, launched in November 1995, has provided extraordinary results concerning the nature of cosmic dust particles. ISO allowed a new definition of the composition of interstellar ices, thermal processing in the protostellar vicinity and gas-grain chemistry. A comparison of interstellar and cometary ices using recent ISO data have revealed important similarities between interstellar ices and volatiles measured in the cometary coma of some comets. The striking identification of fosterite around young Herbig Ae/Be stars and in comet Hale-Bopp, indicate that the disk around such stars could contains comets. The link between processes in dark embedded clouds and comets seems to be evident and studies on the connection between interstellar, cometary and meteoritic dust provide important constraints on the formation of the Solar System and the early evolution on Earth.